OK Walk-in Constant Temperature & Humidity Chamber OK-STH-Series

Overview

The OK Walk-in Constant Temperature & Humidity Chamber OK-STH-Series is an industrial-grade environmental simulation system engineered for system-level reliability validation under controlled thermal and hygrothermal conditions. Designed around the fundamental principles of convective heat transfer and psychrometric control, this chamber employs a cascade refrigeration cycle—comprising independent high-temperature and low-temperature compressor stages—to achieve stable operation across extended temperature ranges from −70°C to +150°C (with humidity capability up to 98% RH). Its walk-in architecture enables direct human access for installation, instrumentation, real-time monitoring, and in-situ adjustment of large-scale test articles, distinguishing it fundamentally from benchtop or upright environmental chambers. The chamber’s structural integrity derives from a welded steel frame, modular insulated panels (double-skin galvanized steel or stainless steel with ≥150 mm polyurethane core, λ ≤ 0.022 W/m·K), and a reinforced hermetic door assembly featuring anti-frost heating, safety interlocks, and optical-grade observation windows. It serves as a foundational infrastructure platform for validating environmental resilience in mission-critical applications where physical size, thermal mass, power dissipation, or operational complexity preclude use of compact test equipment.

Key Features

• Modular, field-assemblable construction supports custom internal volumes—from 1 m³ to over 100 m³—with structural load capacity exceeding 500 kg/m² floor loading.
• Cascade refrigeration system delivers precise sub-ambient performance down to −70°C while maintaining ≤±1°C temperature stability and ≤±3°C spatial uniformity per IEC 60068-3-5 and ASTM E145 Annex A requirements.
• Integrated humidity control subsystem (optional) utilizes steam humidification and deep-coil dehumidification to sustain 20–98% RH with ±3% RH accuracy at 25°C, compliant with ISO 16750-4 and MIL-STD-810H humidity test methods.
• High-efficiency air distribution network—featuring variable-frequency centrifugal blowers and symmetrical duct geometry—ensures airflow velocity ≥0.5 m/s at all measurement points and minimizes thermal stratification.
• Industrial PLC-based controller with 10.4″ color touchscreen HMI supports up to 99 programmable test cycles, each containing 99 segments (ramp/soak), real-time trend display, password-protected parameter editing, and automatic fault logging.
• Comprehensive safety architecture includes dual redundant temperature limiters, refrigerant high-pressure cutouts, door interlocked power shutdown, emergency stop circuitry, and optional CO₂-based fire suppression integration.

Sample Compatibility & Compliance

The OK-STH-Series accommodates physically integrated systems unsuitable for compartmentalized testing—including electric vehicles (EVs), battery energy storage systems (BESS), aerospace avionics racks, telecom base station cabinets, photovoltaic inverters, and full-scale HVAC units. Its open-access interior allows for live cabling via multiple sealed feedthrough ports (IP65-rated, configurable for power, thermocouple, Ethernet, or fiber optic lines), enabling synchronized functional testing under environmental stress. The chamber complies with key international standards governing environmental testing procedures and equipment validation, including ISO 16750-4 (road vehicles), IEC 60068-2-1/2/14/30 (environmental testing fundamentals), MIL-STD-810H Method 502.7/507.6 (temperature/humidity), and EN 60068-2-78 (damp heat, steady state). Optional qualification packages support IQ/OQ documentation aligned with GLP and GMP environments, including calibration traceability to NIST or CNAS-accredited laboratories.

Software & Data Management

The embedded control system records time-stamped temperature, humidity, setpoint, alarm status, and system diagnostics at user-defined intervals (1 s to 60 min resolution). Raw data exports in CSV format are compatible with third-party analysis tools (e.g., MATLAB, Python Pandas, JMP). Optional Ethernet/WiFi connectivity enables remote supervision via web browser or dedicated SCADA client, supporting role-based access control (RBAC) and TLS 1.2 encryption. For regulated industries, an FDA 21 CFR Part 11-compliant software package is available—providing electronic signatures, audit trail with immutable timestamped logs, user activity history, and data integrity verification (SHA-256 hash checksums). All firmware updates undergo version-controlled release validation and include rollback capability.

Applications

• Automotive: Whole-vehicle cold-start validation at −40°C; cabin HVAC performance mapping; battery pack thermal runaway propagation studies under combined temperature/humidity stress.
• Aerospace: Environmental screening of flight-critical line-replaceable units (LRUs); thermal vacuum pre-conditioning of satellite payloads; humidity soak testing of composite airframe sections.
• Energy Storage: Cycle-life assessment of grid-scale BESS enclosures under accelerated temperature-humidity profiles per UL 9540A and IEEE 1679.2.
• Telecommunications: Thermal management validation of 5G macro-cell base stations operating at 55°C ambient with 85% RH; long-term burn-in of edge computing nodes.
• Industrial Electronics: HALT/HASS pre-screening of rail signaling controllers; humidity-induced corrosion testing of PCB assemblies per IPC-J-STD-006.
• Research & Development: Climate chamber for material aging studies (paint adhesion, polymer degradation, sealant compression set) under ISO 4892-2 and ASTM G154 protocols.

FAQ

What is the minimum and maximum standard internal volume offered?
Standard configurations begin at 1 m³; custom builds extend to 200+ m³. Panelized design permits future expansion via additional insulated modules.
Can the chamber operate continuously at −70°C with full humidity control?
Humidity control is disabled below 0°C per psychrometric constraints; sub-zero operation is strictly dry-cold. Humidity functionality is available between +10°C and +85°C.
Is on-site commissioning and validation included?
Yes—factory acceptance testing (FAT) is performed prior to shipment. Site acceptance testing (SAT), including temperature/humidity uniformity mapping per ISO 16750-4 Annex C, is conducted by certified engineers.
How is thermal load from powered devices managed during testing?
Clients must specify maximum internal heat dissipation (kW). OK’s thermal modeling software calculates required refrigeration margin and adjusts compressor staging, airflow, and condenser cooling capacity accordingly.
Are spare parts and service support available globally?
OK maintains regional technical service hubs in Germany, USA, and Singapore, with 48-hour response SLA for critical failures. All major subsystems—including compressors, PLCs, and humidifiers—are sourced from Tier-1 industrial suppliers with ≥10-year part availability guarantees.